I’m not a fan of chicken-fights either (thats what its called where I come from) but I did attend the fights when I was in San Juan.
One thing I noticed in comparison to the (one) fight I attended years ago in my home state. Where I come from the fights were to the death. The knives attached to the feet were quite sharp and did a lot of damage. They did not stop the fight until one of the chickens was dead; even going to what I thought were ridiculous lengths when it was clear the loser was the loser.
The fights in PR seem to go only to the point that you have a clear winner, when one chicken clearly dominated the other. Most of the time both chickens survived. It seemed to me to be much more humane than what I had seen on the mainland. The knives were not the same either and didn’t do nearly the damage I had seen where I come from.
Another point, I saw that chicken fights were very widespread in Venezuela, which means this is not some kind of cultural anomaly. It may not be my cup of tea, but part of being free is letting your neighbor be free too.